Motor vehicles are typically equipped with emission control systems in order to meet regulated emission standards. In order to better control emissions, it is beneficial for the emission control system to know the composition of the fuel being consumed by the engine (e.g. ethanol content in gasoline or methane concentration in compressed natural gas). In many systems, the regulated monitoring of certain emission related components and systems are disabled during the fuel composition determination process. As such, emission control performance may be less than optimal until the fuel composition is determined by the emission control system. It is preferable to initiate this process whenever a change in the fuel composition may have occurred, such as when an increase in the amount of fuel in the fuel tank is detected, i.e. a refueling event is detected. However, regulatory requirements (such as section 1968.2 of title 13, California Code of Regulations) do not allow for the disablement of regulated emission related monitoring for unsubstantiated reasons such as erroneous detection of refueling events due to refueling event detection system malfunctions. Therefore, it is desirable to be able to diagnose the performance of a refueling event detection system.